In the field of communications, a tunnel is a transmission channel for bearing a service. One tunnel can bear multiple types of services (Class Type, CT), and different CTs are differentiated by using different priorities. Therefore, the tunnel can provide transmission services of different priorities for services that have different requirements of quality of service (Quality of Service, QOS), so that a network resource is fully utilized according to a user requirement.
An existing traffic engineering (Traffic Engineering, TE) tunnel, Internet protocol (Internet Protocol, IP) tunnel, label switched path (Label Switched Path, LSP) tunnel and so on can support simultaneous transmission of multiple services of different CTs (which may be referred to as different services), and a service class of a different service may be identified by using a priority identification field, where the priority identification field is generally used as a flag of a QOS service level.
With the constant development of a network and service, QOS of a service has become a hot topic of network research, and how to provide reliable and guaranteed service is a problem commonly concerned by operators. Performance parameters such as packet loss, delay, and variation, which are used as effective tools for measuring a service level of a service, are increasingly concerned by equipment suppliers and operators; however, performance parameters such as packet loss, delay, and variation still cannot be measured for different services transmitted in a same tunnel in the conventional technology.